1 Trim the fillet of all silver skin and sinew. Roll the meat in a mixture of cracked szechuan pepper, black pepper and oyster sauce.
2 Tightly wrap the fillet in clingfilm to form it into an regular shape and seal in the marinade. Refrigerate for several hours.
3 Makea sauce by reducing a good liquid (not powder) beef stock by half or until it will coat a spoon. Add a decent slug of whiskey and check the seasoning. Keep warm.
4 Make a purée of golden kumara: boil peeled kumara chunks, dry, mash with butter and pass through a sieve or mouli. Season well with salt and pepper, keep warm.
5 Cook the trimmed asparagus spears in salted water. Drain and keep warm.
6 Remove the fillet from the fridge and allow to come to room temperature.
7 Put a baking dish with 2 tablespoons of oil into the oven, set on high. Once the tray is well heated, carefully roll the fillet in the hot oil, close the oven door and cook for 5 minutes before reducing the heat to medium.
8 Cook a further 10 minutes and then remove the fillet from the oven, cover and allow to rest for at least 10 minutes.
9 Slice the meat into portion size.
10 Add any juices from the resting to your warm sauce. Bring this sauce up to a boil, take off the heat and swirl in a knob of butter.
11 On warm dinner plates, make a bed of kumara purée and arrange the asparagus. Place the fillet slice on top of the kumara and be liberal with the whiskey jus. Any extra can be served in a warm gravy boat on the table.
